Power (measured in watts) and efficiency (how well panels convert sunlight to electricity) are some of the most common metrics used to compare solar panel products. While they are not the only means of comparison, they are important determinants in how much electricity you can produce with a solar panel system. Metrics like power tolerance and temperature coefficient are also important ways to analyze the potential performance of solar panels under the different conditions they will experience over their lifetime.

Solar panels generally come with an output warranty covering the energy production of the panel, and a materials warranty protecting you against undue wear and tear on your equipment. Learn more about solar panel warranties.

Solar panels typically have black or blue cells, white, silver, or black backsheets, and silver or black frames. Bifacial solar panels are one exception to these rules, as they have transparent backsheets.

The physical characteristics of a solar panel have an impact on the product’s performance. For example, metrics like efficiency and wattage are based on the type, size, and number of solar cells used in a panel.

Solar panels are made all around the world. While the bulk of solar panel manufacturers are based in Asia, companies in the United States, Canada, and other countries also produce high-quality photovoltaics.

Organizations like the International Electrotechnical Commission (IEC) and Underwriters Laboratories (UL) create national and international standards for photovoltaic solar panels to ensure any products on the market meet certain specifications for safety and reliability reasons.